Rubberized fabric to be used in flexible oilproof containers generally had a construction as illustrated in FIG. 1. In this construction, for example, a coating of an oilproof synthetic rubber 2 (such as nitrile rubber or urethane rubber) is applied on each side of a woven fabric of nylon 1.
Where a container using a diaphragm and having fuel oil as its container is desired to curb loss of the fuel oil due to permeation through the diaphragm with great exactitude or where the thickness or weight of the diaphragm is specifically desired to be decreased, however, the rubberized fabric is produced in a construction as illustrated in FIG. 2. In this construction, an adhesive agent layer 4 for the composition is superposed on a rubber layer 2 applied as a coating on at least one side of the woven fabric, a resin layer (called a "barrier" layer) 3 for curbing passage of fuel oil is superposed on the adhesive agent layer 4, an adhesive agent layer 4 is again superposed, and an outermost rubber layer 2 is deposited as a coating thereon. The barrier 3 constitutes itself a continuous face and the rubber layers 2 on both sides of the barrier function to protect the barrier. The interlayer adhesive 4 selected in view of the composition of the rubber 2 and the barrier 3. The woven fabric 1 in either of the constructions of FIG. 1 and FIG. 2 is treated with adhesive agent for the purpose of composition with the rubber layers 2 on both sides thereof.
By this construction, the loss of fuel oil due to permeation through the diaphragm can be curbed and the thickness and/or weight of the diaphragm can be reduced. The construction nevertheless entails the following drawbacks.
(1) The rubberized fabric is expensive. PA0 (2) Lack of structural or physical symmetry between the opposite sides of woven fabric
As is apprent from the construction, the production of this rubberized fabric calls for many steps of operation. More often than not, the adhesive agent layers and the barrier are required to have a limited thickness falling generally in the range of 20 to 50 .mu.m. Thus, the operation necessitates an advanced coating technique and many steps (because of many applications each in as small a thickness as permissible) or a laminating technique.
Generally, due to cost, the adhesive agent layer and the barrier are each formed only on one of the sides of the woven fabric. Thus, the two sides of the rubberized fabric are structurally asymmetrical relative to the woven fabric. When the rubberized fabric is folded over itself, for example, the barrier and the adhesive agent layer which have relatively high rigidity are liable to gather stress possibly so much as to sustain breakage.
Further, the side of the rubberized fabric containing the adhesive agent layer and the barrier has a rubber content proportionately lower because of the presence of these layers. At low temperatures, the overall rigidity of this side of the rubberized fabric is so high that the side is liable to sustain cracks if the rubberized fabric is folded.